I don't know about anyone else, but for me I sometimes get quoted in a thread, and never realize it because I haven't kept tabs on the thread anymore or I just glimpsed over it accidentally. Is it possible to implement a system where you get a private message (or something similar) if you are quoted in a thread?

Over at slickdeals.net, if you are quoted in a thread, it tells you with a little pop up at the bottom right hand side of the screen. I think this would help a lot of the people who are active on the forums and post on a lot of threads.